the olecranon and adjacent upper third of the ulna.

DEEP LAYER. Supinator Brevis. Origin, external
lateral ligament, orbicular ligament, supinator ridge,
oblique line of the ulna, and for a short distance on
the outer border of the ulna from the fascia covering
it, which is connected with the external condyle; it
regularly consists of two layers separated by the
posterior interosseous nerve; the superficial one rises
by aponeurotic fibers, the other by muscular. The
fibers pass sling-like around the upper part of the
radius to be inserted into a third of its length, limited



156 MUSCLE TISSUE

by the anterior and posterior oblique lines to its neck
and elbow-joint capsule.

Extensor Ossis Metacarpi Pollicis. Origin, upper
part of the outer division of the posterior surface of
the ulna below the supinator brevis, from the middle
third of the posterior surface of the radius and inter-
osseous membrane between. Its tendon passes over
those of the radial extensors, and is inserted into the
radial side of the base of the metacarpal bone of the
thumb, and commonly by a slip into the trapezium,
its tendon usually splitting.

Extensor longus pollicis arises below the extensor
ossis on the middle third of the ulna and from the
interosseous membrane for about one inch; its tendon
passes over the radial extensors, and is inserted into
the posterior aspect of the base of the last phalanx of
the thumb.

Extensor Indicis Proprius.- Origin, from the ulna
below the extensor longus pollicis, and slightly from
the interosseous membrane and fascia over the exten-
sor carpi ulnaris; unites with the common extensor
tendon for the index, and forms the usual insertion.
This and the extensor minimi digiti tendon are always
on the ulnar side of the respective common extensor
tendons.

Extensor Brevis Pollicis. Origin, small part of the
interosseous membrane and radius below the middle,
next below the extensor ossis; insertion, upper end of
the first phalanx of the thumb on its posterior aspect.

The Muscles and Fasciae of the Hands

Fascia of the posterior aspect is a thin layer prolonged
from the posterior annular ligament and blending with
the extensor expansions over the fingers; deeper than
this the interossei are covered by thin aponeuroses.

Fascia of the palm consists of a strong central
part and two lateral portions which cover the short



MUSCLES AND FASCIA OF UPPER EXTREMITY 157

muscles of the thumb and little finger. The central
portion is the part commonly called the palmar fascia;
it consists of fibers mostly prolonged from the palmaris
longus, some from the annular ligament, thus form-
ing two superficial layers with vertical fibers, between
which is the palmaris brevis muscle; there is a deep
layer of transverse fibers. Below, the fa'scia divides
into four processes to join the digital sheaths; offsets
are sent back to the deep transverse ligament at the
heads of the metacarpals, forming a short canal above
each finger for the flexors. Between the processes
the transverse layer of fascia covers the lumbrical
muscles, digital vessels, and nerves, passing over
to the thumb and forefinger. At the clefts of the
fingers a transverse band is called the superficial
transverse ligament, or Gerdy's fibers. The interossei
muscles also have a separate fascia continued below
into the deep transverse ligament.

The Radial Region. The following muscles consti-
tute the thenar eminence (the fleshy prominence of the
palm corresponding to the base of the thumb) and
have a great variety of description.

Abductor pollicis. Adductor pollicis, obliquus.

Plexor brevis pollicis. Adductor trans versus
Opponens pollicis. pollicis.

The Ulnar Region. The following muscles constitute
the hypothenar eminence. (The fleshy prominence of
the palm corresponding to the fleshy part over the
metacarpal bone of the little finger.)

Abductor minimi digiti. Opponens minimi digiti.

Flexor brevis minimi digiti. Palmaris brevis.

The Middle Palmar Region. The dorsal interossei
are four in number, one for each space, not rising
above the level of the bones, and numbered from
without inward. Each rises from the two bones



158 MUSCLE TISSUE

between which it is placed, most extensively from
that supporting the finger upon which it acts. The
tendon is inserted partly into the base of the first
phalanx and partly into the extensor tendon.

The palmar inter ossei are three in number, are adduc-
tors, and each rises' from the lateral surface of the meta-
carpal of the finger on which it acts. They terminate
like the posterior tendons. The first belongs to the
ulnar side of the index, the second and third to the
radial sides of the ring and little fingers.

The lumbricales are four small muscles, not always
well-defined. They arise from the tendons of the flexor
profundus digitorum.

ACTIONS OF MUSCLES OF THE FOREARM AND HAND.
Pronation by the pronator teres and quadratus
and flexor carpi radialis slightly; pronator teres
flexes the forearm; can only pronate when the radius
is intact.

Supination by the supinator brevis, biceps, and
supinator longus; the latter is a flexor of the elbow
and brings the forearm into midsupination. Radial
extensors of the wrist flex the elbow; others from the
external condyle extend.

Flexion */ the wrist by the flexor carpi ulnaris and
radialis, by the flexors of the fingers and palmaris
longus.

Extension of the wrist by the extensor carpi ulnaris,
the two radial extensors, and extensors of the fingers.

Abduction of the wrist by the radial flexor and radial
extensors and extensors of the thumb.

Adduction of the wrist by the flexor and extensor
carpi ulnares. The flexor carpi radialis and extensor
carpi ulnaris act on the radiocarpal joint; the flexor
carpi ulnaris and radial extensors on the midcarpal
joint.

The extensors of the wrist are moderators of the
long flexors of the fingers; the flexors of the wrist
are moderators of the extensors of the fingers.



MUSCLES AND FASCIA OF LOWER EXTREMITY 159

The posterior interossei abduct the fingers from the
middle one; the palmar adduct; the interossei and
lumbricales flex the first phalanx and extend the last
two.

Flexion in the fingers. Extension in the fingers.

First phalanx, by the interossei By the extensor communis.

and lumbricales.

Second phalanx, by the flexor By the interossei and lumbri-

sublimis. cales.

Third phalanx, by the flexor By the interossei and lumbri-

profundus. cales.

When we flex the fingers they tend to approach, due
to the lateral ligaments and obliquity of the tendons.

The palmaris longus makes tense the palmar fascia,
feebly flexes the forearm and wrist; all the muscles
from the condyle feebly flex the forearm.

Palmaris brevis wrinkles the skin over the hypothe-
nar eminence and protects the ulnar vessels and nerve
from pressure when a foreign body is grasped.

Extension in the thumb is in the plane of abduction
of the fingers, and its abduction is a movement forward.
The action of its muscles and those of the little finger
are indicated by their names; the flexors of the first
phalanx in either case also extend the last, as the inter-
ossei would. The ulnar extensor and flexor of the
carpus are moderators of the thumb extensors. There
are three flexors of the wrist (including the palmaris
longus) and three extensors, three flexors of the fingers
and three extensors, three flexors of the thumb and
three extensors.



THE MUSCLES AND FASCLE OF THE LOWER
EXTREMITY

Fasciae of the Thigh

The superficial fascia is continuous with that of
other parts of the body.



160 MUSCLE TISSUE

The deep fascia or fascia lata is a strong membrane
forming a continuous sheath around the limb. It
descends on the gluteus medius as far as the upper
border of the gluteus maximus, which muscle it encases,
and over the great trochanter a great part of the muscle
is inserted between its layers. From the forepart
of the iliac crest to the outer tuberosity of the tibia
is the iliotibial band, which receives the insertions
of the tensor vaginae femoris and gluteus maximus
muscles.

The fascia lata has various deep processes; one is
internal to the tensor vaginse femoris on the surface
of the vastus externus.

There are external and internal intermuscular septa
inserted into the linea aspera.

The Gluteal Region (Buttocks)

Gluteus Maximus. A quadrilateral, very coarse
muscle. Origin, posterior fourth of the external lip
of the iliac crest and rough surface between it and the
posterior gluteal line, the last two pieces of the sacrum
and first three of the coccyx, great sacrosciatic liga-
ment, and aponeurosis of the erector spinse.

The upper half and superficial fibers of the lower half
are inserted into the fascia lata and continued into the
iliotibial band; the deeper portion of the lower half
into the gluteal ridge on the upper third of the shaft
of the femur.

Gluteus Medius. Origin, ilium between the crest,
the posterior and middle curved lines, and from the
fascia covering it; to insert on the outer surface of the
great trochanter; a small bursa between the bone and
tendon.

Gluteus minimus is covered by the preceding, and
arises from the whole surface on the ilium between the
middle and inferior curved lines, fibers converge into
an aponeurotic tendon on the outside of the muscle,



MUSCLES AND FASCIA OF LOWER EXTREMITY 161

inserted into an impression on the front of the great
trochanter.

Actions of the glutei on the lower limb:



Flexion.

Glut, med., anterior fibers.
Glut, min., anterior fibers.

Adduction.
Glut, med., anterior fibers (in

sitting posture.
Glut, min., anterior fibers (in

sitting posture).

Rotate in.

Glut, med., anterior fibers.
Glut, min., anterior fibers.



Extension.
Glut, maximus.
Glut, med., posterior fibers.
Glut, min., posterior fibers.

Abduction.
Glut., max., slight.

{strong, whole
muscle, espe-
cially mid-
portion.

Rotate out.
Glut. max.

Glut, med., posterior fibers.
Glut, min., posterior fibers.



The glutens maximus extends the trunk on the thigh
as in ascending stairs; in walking it is not used, as the
erect position is maintained by ligaments; steadies
and supports the knee by the iliotibial band.

The iliopsoas flexes the thigh and rotates out; flexes
the body on the thigh; the psoas bends the lumbar
spine forward and laterally.

Psoas parvus makes tense the iliac fascia.



The Thigh Muscles

These are arranged in three sets anterior, poste-
rior, and internal, with superficial and deep layers, the
former passing over two joints, the latter over one.

The Anterior Femoral Region. Tensor vaginae femoris
(tensor fascise) lies in a groove between the gluteus
medius, rectus, and sartorius. Origin, anterior part
of the external lip of the iliac crest, notch between
the two spines; insertion, between the two layers of
the fascia lata three or four inches below the great
trochanter, and from the insertion fibers are prolonged
into the iliotibial band,
11



162 MUSCLE TISSUE

Sartorius ( Tailor Muscle) . Origin, anterior superior
spine of the ilium and small part of the notch imme-
diately below; insertion, inner surface of the tibia near
the tubercle, sending an expansion from the upper
border to the capsule, one from the lower border to
the fascia of the leg, and one to the tibia behind the
tendons of the gracilis and semitendinosus.

Quadriceps Femoris. Largest muscle of the body,
four parts closely united, (a) Rectus femoris, in a
straight line from the pelvis to the patella. Origin,
by two heads, anterior one from the anterior inferior
spine, and posterior from the impression just above
the acetabulum; they join at an angle of 60 degrees
close below the acetabulum; the tendon is anterior
above, then in centre of the muscle. The lower tendon
becomes free three inches above the patella ; is attached
to the upper margin of that bone, and helps form the
common tendons.

(6) The vastus externus is the outer part of the quad-
riceps. Origin, narrow and aponeurotic from the upper
half of the anterior intertrochanteric line, outer part
of the root of the great trochanter, outer side of the
gluteal ridge, upper half of the outer lip of the linea
aspera, from external intermuscular septum, and a
strong aponeurosis extending over the upper tw T o-
thirds of the muscle. Aponeurosis of insertion occupies
the deep surface of the muscle, joins the common
tendon, and sends expansion to the lateral patellar
ligaments and rectus tendon.

(c) The vastus internus arises from a superficial
aponeurosis and deeper fibers from the spiral line,
inner lip of the linea aspera, and from tendons of the
adductor longus and magnus; they end in a deep
aponeurosis which enters the common tendon. Its
muscular fibers pass lower than those of the externus,
and are inserted into the inner margin of the patella,
some into the rectus tendon.

Crureus arises from upper two-thirds of the anterior



MUSCLES AND FASCIA OF LOWER EXTREMITY 163

surface of the femur, outer surface of the femur in
front of and below the vastus externus, lower half
of the external intermuseular septum; fibers end in a
superficial aponeurosis which forms the deepest portion
of the common tendon. They arise from a series of
transverse arches with intervening bare spaces on
the front of the femur. Between the crureus and the
vastus internus most of the internal surface of the bone
is free.

The common or suprapatellar tendon is inserted into
the forepart of the upper border of the patella, and a
few fibers are prolonged over its anterior surface into
the ligamentum patellae. A large, thick ligament sur-
rounding the patella and inserted into the tubercle of
the tibia.

Subcrureus is the name of a few fibers which may be
regarded as the deepest layer of the crureus. Origin,
anterior surface of the femur in the lower fourth;
insertion, separated by a fat layer from the vasti into
the synovial membrane of the knee-joint.

Hunter's canal is a three-cornered passage in the
middle two-fourths of the thigh, in the angle between
the adductors magnus and longus and vastus internus.
It is made a canal by a bridge of fascia, and contains
the femoral artery, vein, and long saphenous nerve.

Nerves. Anterior crural for the quadriceps and
sartorius; superior gluteal for the tensor vaginae femoris.

Actions. Satorius flexes the hip and knee with
e version of the thigh; rotates the leg inward.

Quadriceps femoris extends the leg; not necessary
for the maintenance of the erect attitude.

Rectus femoris also flexes the hip; its posterior head
is tense when the thigh is bent. Lower fibers of the
vastus internus draw the patella in.

Tensor vagina femoris rotates the thigh in and
abducts, assisted by the gluteus maximus; counter-
acts the gluteus maximus, which tends to draw the
iliotibial band backward.



104 MUSCLE TISSUE

The Posterior Femoral Region (Hamstrings). Biceps
Femoris. Origin, long head by a tendon common to
it and semitendinosus from inner impression on the
lower part of the ischial tuberosity, and from the
sacrosciatic ligament; short head from the lower two-
thirds of the outer lip of the linea aspera and external
intermuscular septum; fibers from 'both heads end
in a tendon inserted into the upper and outer part of
the head of the fibula by two portions embracing the
external lateral ligaments.

Semitendinosus. Arises from the tuberosity of the
ischium and tendon common to it and biceps for 3
inches. Terminates in the lower third of the thigh in
a long, slender tendon, and curves forward in an ex-
panded form to insert on the upper part of the inner
surface of the tibia or anterior crest of the tibia, and
sends a process to the fascia of the leg.

Semimembranosus. Origin, tuberosities of the ischium
above and outside the tendon of the biceps and semiten-
dinosus, and its tendon is grooved posteriorly for the
common tendon of those two muscles. Tendon of origin
is on the outer side of the muscle for three-fourths the
length of the thigh ; tendon of insertion, on the opposite
side of the muscle, and turns forward and is inserted by
four parts: (1) into a horizontal groove on the back of
the inner tuberosity of the tibia; (2) expansion is sent
up and in as the posterior oblique ligament of the knee-
joint; (3) down to the fascia over the popliteus muscle;
(4) to form the short internal lateral ligament of the
knee-joint.

The Internal Femoral Region. Pectineus. Origin,
iliopectineal line, and slightly from bone in front of
this, and from the fascia over the muscle; insertion,
femur behind the small trochanter and upper part
of the line passing from this trochanter to the linea
aspera.

Adductor Longus. Flat and triangular, internal to
the pectineus, on same plane. Origin, short tendon



FIG. 69



Fia. 70




Muscles in the dorsum of the right
thigh. (Testut.)



Adductores magnus and brevis of
the right side. (Testut.)



166 MUSCLE TISSUE

from the body of the pubis below the crest and near
the angle; insertion, inner lip of the linea aspera, united
to the vastus internus in front and adductor magnus
behind.

Gracilis. Origin, inner margin of pubic bone and a
portion of its inferior ramus ; thin and flat, then narrow
and thicker. A round tendon in the lower third of the
thigh, curving forward below, inserted into the inner
side of the tibia just above the semitendinosus, and
covered by the sartorius.

Adductor Brevis. Origin., body and inferior ramus of
the pubis below the adductor longus, between the gra-
cilis and obturator externus; insertion, into the whole
line from the small trochanter to the linea aspera
behind the pectineus. It lies between the adductor
magnus and longus.

Adductor Femoris Minimus. This is what is de-
scribed with the adductor magnus, usually as its
anterior and superior portion. Origin, body of the
pubis and ischiopubic rami; insertion, femur, in a line
from the quadratus femoris to the upper end of the
linea aspera, and a short distance along it.

Adductor Magnus. Origin, ischial ramus internal
to the above muscle and outer half of the triangular
space on the posterior inferior surface of the tuberosities
of the ischii; fibers pass in two layers, one to the inner
lip of the linea aspera, and the other on the inner side
of the opening for the femoral vessels by a distinct
rounded tendon to insert on the adductor tubercle on
the inner condyle of the femur. The femoral attach-
ment is interrupted by three or four tendinous arches
for the perforating arteries.

Actions. All adduct the thigh. Pectineus, adductor
longus and brevis flex the hip, while part of adductor
magnus from the ischial tuberosity to the condyle
may extend the thigh and rotate in. Gracilis flexes
the knee and rotates the leg inward. Adductors and
opponens, the gluteals, balance the body in walking.



MUSCLES AND FASCIA OF LOWER EXTREMITY 167

(1) Anterior fibers of the gluteus medius (2) and
minimus; (3) tensor vaginae femoris; and some say (4)
the condylar part of the adductor magnus, rotate the
thigh inward.

Muscles of the Leg

The Anterior Tibiofibular Region (Extensors). Tibi-
alis Anticus. Origin, outer tuberosity of the tibia,
upper half of the outer surface of that bone, and
adjacent interosseous membrane, fascia of the leg,
and intermuscular septum; insertion, oval mark on the
inner and lower part of the internal cuneiform and first
metatarsal dividing into two slips.

Extensor Longus or Proprius Hallucis. Origin,
middle two-fourths of the narrow anterior surface of
the fibula and contiguous portion of the interosseous
membrane; insertion, base of the terminal phalanx of
the great toe on the dorsal aspect. It spreads in an
expansion on each side over the metatarsophalangeal
articulation, and almost always sends a slip to the
base of the first phalanx.

Extensor Longus Digitorum Pedis. Origin, external
tuberosity of the tibia, head, and upper two-thirds of
the anterior surface of the fibula, very largely from
the septa and fascia and interosseous membrane above
the origin of the extensor proprius hallucis. Tendon
divides into four slips for the outer four toes. They
are continued into expansions which are joined on
the first phalanx by processes from the interossei
and lumbricales. They divide into three parts the
middle inserted into the middle phalanx; the lateral
parts unite, and are inserted into the base of the
terminal phalanx as in case of the extensors of the
fingers.

Peroneus Tertius. Origin, lower third or more of
the anterior surface of the fibula, from the interosseous
membrane, from the septum between it and the



168 MUSCLE TISSUE

IHToneus brevis; insertion, upper surface of the base
of the fifth metatarsal, sometimes the fourth. This
muscle is peculiar to man.

The Fibular or Peroneal Region. Peroneus Long us. -
Origin, head and upper two-thirds of the external
surface of the fibula, fascia of the leg, and septa on
each side. Tendon begins in the lower half of the leg,
passes behind the external malleolus; then forward on
the outer side of the os calcis, winds around the tuber-
osity of the cuboid, and enters its groove, crosses the
sole obliquely, and is inserted into the outer side of
the tuberosity of the first metatarsal, and slightly
into the internal cuneiform; a frequent offset to the
base of the second metatarsal and first dorsal inter-
osseous.

Peroneus Brevis. It lies deeper than the peroneus
longus. Origin, lower two-thirds of the external surface
o'f the fibula from the septa and a flat tendon on the
surface turned toward the bone; insertion, tuberosity
at the base of the fifth metatarsal, sending a small slip
to the outer edge of the extensor of the little toe or
forepart of the metatarsal bone.

The Posterior Tibiofibular Region (Flexors). Super-
ficial Muscles. Gastrocnemius. Gastrocnemius has
two large heads from the femur, terminating at the
middle of the leg in a common tendon. Outer head
from the depression on the outer side of the external
condyle above the tuberosity, and from the posterior
surface of the femur just above that condyle. Inner
head from the upper part of the internal condyle.
The two heads join with the soleus and are inserted
into the tendo Achillis.

Soleus. Origin, externally from the posterior sur-
face of the head and upper third of the shaft of the
fibula; internally, oblique line and inner border of the
tibia to its middle, and from a tendinous arch over
the popliteal vessels and nerve; fibers rise to a large
extent from two tendinous laminae which descend



MUSCLES AND FASCIA OF LOWER EXTREMITY 169

in the muscle, one from the fibula and one from the
tibia. Fibers from the anterior surfaces of these laminae
converge to a median septum; fibers from their pos-
terior surfaces pass down and back to an aponeurosis
covering the back surface of the muscle. The tendon
of insertion is prolonged from this aponeurosis, joined
by the median septum. Muscular fibers are continued
down on the deep surface of the tendo Achillis near
to the heel.

The gastrocnemius and soleus form the calf of the leg.

Tendo Achillis, broad at fir^t, contracts to within
1J inches of the heel, then expands, and is inserted
into the middle and lower parts of the posterior surface
of the tuberosity of the os calcis, a bursa having all
the characters of a synovial membrane, with vascular
and fatty synovial tufts, separating it from the upper
part of this surface.

Plantaris. Origin, femur above the external condyle
and from the posterior ligament of the knee-joint.
Muscular belly 3 to 4 inches long, and the long, slender
tendon turns in between the gastrocnemius and soleus
to the inner border of the tendo Achillis, and inserted
by its side into the os calcis.

Popliteus. Origin, round tendon, one inch long, from
the groove on the outer surface of the external condyle
of the femur, within the capsule of the joint, in contact
with the semilunar cartilage, and by muscular fibers
from the ligamentum popliteus arcuatum. Fibers
pass down and are inserted into the triangular surface
of the tibia above the oblique line, and into the
aponeurosis over the muscle.

THE DEEP MUSCLES (Flexors) Flexor Longus Digi-
torum Pedis. Origin, inner portion of the posterior
surface of the tibia for the middle two-fourths of its
length, from the aponeurosis over the tibialis posticus.
Descends behind the internal malleolus of the tibia,
passes forward and obliquely outward, having crossed
the tibialis posticus tendon in the leg, and now crossing



170 MUSCLE TISSUE

that of the flexor longus hallucis, in each case super-